Synthesis and characterization of an osmium porphyrinato bis(arylimido) complex, Os(TTP)(NAr)2, with strongly bent osmium-organoimido bonds

Ruthenium Porphyrins with Axial π‐Conjugated Arylamide and Arylimide Ligands

“…The computed C‐N imide ‐N mide ‐C torsion angle of −0.3° (C21‐N5‐N6‐C33, Table 3) is close to 0° and is comparable to those in the crystal structures of [Ru VI (tmp)(N{ Ar  Ar ‐ p ‐OMe}) 2 ] (−14.6°) and previously reported [Ru VI (tpp)(N{Ar‐3,5‐CF 3 }) 2 ]8 (5.7°), [Os VI (ttp)(N{Ar‐ p ‐NO 2 }) 2 ]13a (−2.5°) and [Os VI (4‐Cl‐tpp)(N{Ar‐ p ‐NO 2 }) 2 ]13b (−5.9°). In contrast, a large C‐N amide ‐N amide ‐C torsion angle of 180° has been found in the DFT‐optimized structure of [Ru IV (por 0 )(NHPh) 2 ] reported previously40 and in the crystal structure of [Ru IV (tmp)(NH{ Ar  Ar ‐ p ‐OMe}) 2 ].…”

“…The N imide ‐Ru‐N imide axis is appreciably bent in both the DFT‐optimized structure of [Ru VI (tmp)(N{ Ar  Ar ‐ p ‐OH}) 2 ] and the crystal structure of [Ru VI (tmp)(N{ Ar  Ar ‐ p ‐OMe}) 2 ] (N5‐Ru1‐N6 angle: 169.0° and 172.8(2)°, respectively; Table 3), with the two trans arylimide ligands bending to the same side to give the syn configuration. A similar syn configuration with an appreciably bent N imide ‐M‐N imide axis has also been found for the previously reported crystal structures of several d 2 metal–bis(arylimide) porphyrins including [Ru VI (tpp)(N{Ar‐3,5‐CF 3 }) 2 ],8 [Os VI (ttp)(N{Ar‐ p ‐NO 2 }) 2 ],13a and [Os VI (4‐Cl‐tpp)(N{Ar‐ p ‐NO 2 }) 2 ]13b (N imide ‐M‐N imide angles: 165.1(2)°–167.97(18)°). This is different from the linear N amide ‐Ru‐N amide axis (with an angle of 180°) in the DFT‐optimized structure of [Ru IV (por 0 )(NHPh) 2 ]40 and the crystal structure of [Ru IV (tmp)(NH{ Ar  Ar ‐ p ‐OMe}) 2 ] both with anti configuration.…”

“…For [Ru VI (tmp)(N{ Ar  Ar ‐ p ‐OH}) 2 ], the N5/N6 orbital used for the π‐bonding of N imide RuN imide (N5Ru1/N6Ru1) has 4.3 % s orbital and 95.7 % p orbital characters (from NBO analysis). We further performed DFT calculations on the structurally characterized [Ru VI (tpp)(N{Ar‐3,5‐CF 3 }) 2 ],8 [Os VI (ttp)(N{Ar‐ p ‐NO 2 }) 2 ],13a and [Os VI (4‐Cl‐tpp)(N{Ar‐ p ‐NO 2 }) 2 ],13b which gave geometrical parameters in good agreement with those in their crystal structures (Table S7 in the Supporting Information) and revealed similar s orbital characters of 6.6, 7.5, and 7.5 %, respectively, in the corresponding N(imide) (N5/N6) orbital used for the N imide MN imide π‐bonding. We suggest that, for these metal–bis(arylimide) complexes, the slight mixing of the 2 s and 2 p orbitals of N(imide) atom leads to an appreciably bent N imide ‐M‐N imide (M=Ru, Os) axis that gives the syn configuration allowing for a better π‐overlap between Ru/Os and N(imide) (Figure 10) and/or a better π‐bonding along CN imide MN imide C (such as C21N5Ru1N6C33 in Figure 8).…”

Synthesis, characterisation and reactivity of novel bis(tosyl)imidoruthenium(vi) porphyrin complexes; X-ray crystal structure of a tosylamidoruthenium(iv) porphyrin

“…The IR spectra of 1 and 2 exhibit intense n as (RuNNTs) stretching absorptions at 914 and 900 cm 21 respectively, which are at lower wavenumbers than the n as (OsNNTs) absorption at 924 cm 21 found in [Os VI (tpp)(p-NC 6 H 4 NO 2 ) 2 ]. 12 It is important to note that the oxidation state markers for 1 and 2 appear at 1016 and 1018 cm 21 respectively, which is in accordance with the formulation of the ruthenium(vi) oxidation state. 10a,11 The diamagnetic behaviour of the complexes, together with the above findings, strongly suggest a terminal d 2 metal-imido system.…”

Terminal Nitrido and Imido Complexes of the Late Transition Metals

“…[241][242][243] Although Os analogs are known, [241,[244][245][246][247] the Ru di-imido complexes have been found to catalyze a number of organic reactions, including olefin aziridination and NR insertion into CÀH bonds. [248][249][250][251] In analogy to the well-known trans-dioxo-Ru(VI) complexes, a (d xy ) 2 ground state is expected for these di-imido compounds.…”